Date: Fri, 28 Oct 11 00:07:55 GMT Subject: nucl-th daily 6 new + 8 crosses received by eprepget ------------------------------------------------------------------------------ ------------------------------------------------------------------------------ Send any comments regarding submissions directly to submitter. ------------------------------------------------------------------------------ Archives at http://arxiv.org/ To unsubscribe, e-mail To: nucl-th@arXiv.org, Subject: cancel ------------------------------------------------------------------------------ received by eprepget from Wed 26 Oct 11 20:00:00 GMT to Thu 27 Oct 11 20:00:00 GMT ------------------------------------------------------------------------------ \\ arXiv:1110.5923 Date: Wed, 26 Oct 2011 20:19:49 GMT (1749kb) Title: Non-exponential decay in quantum field theory and in quantum mechanics: the case of two (or more) decay channels Authors: Francesco Giacosa Categories: nucl-th hep-ph quant-ph Comments: 30 pages, 10 figures \\ We study the deviations from the exponential decay law, both in quantum field theory (QFT) and quantum mechanics (QM), for an unstable particle which can decay in (at least) two decay channels. After a review of general properties of non-exponential decay in QFT and QM, we evaluate in both cases the decay probability that the unstable particle decays in a given channel in the time interval between $t$ and $t+dt.$ An important quantity is the ratio of the probability of decay into the first and the second channel: this ratio is constant in the Breit-Wigner limit (in which the decay law is exponential) and equals the quantity $\Gamma_{1}/\Gamma_{2}$, where $\Gamma_{1}$ and $\Gamma_{2}$ are the respective tree-level decay widths. However, in the full treatment (both for QFT and QM) it is an oscillating function around the mean value $\Gamma_{1}/\Gamma_{2}$ and the deviations from this mean value can be sizable. Technically, we study the decay properties in QFT in the context of a superrenormalizable Lagrangian with scalar particles and in QM in the context of Lee Hamiltonians, which deliver formally analogous expressions to the QFT case. \\ ( http://arxiv.org/abs/1110.5923 , 1749kb) ------------------------------------------------------------------------------ \\ arXiv:1110.5943 Date: Wed, 26 Oct 2011 22:24:11 GMT (1487kb,D) Title: Nuclear Physics from Lattice QCD Authors: Martin J. Savage Categories: nucl-th hep-lat hep-ph Comments: 18 pages, 12 figs. Lecture presented at the Erice School on Nuclear Physics 2011: From Quarks and Gluons to Hadrons and Nuclei, organized by A. Faessler and J. Wambach Report-no: NT@UW-11-027 \\ I review recent progress in the development of Lattice QCD into a calculational tool for nuclear physics. Lattice QCD is currently the only known way of solving QCD in the low-energy regime, and it promises to provide a solid foundation for the structure and interactions of nuclei directly from QCD. \\ ( http://arxiv.org/abs/1110.5943 , 1487kb) ------------------------------------------------------------------------------ \\ arXiv:1110.5982 Date: Thu, 27 Oct 2011 04:51:03 GMT (284kb,D) Title: Compton Scattering and Photo-absorption Sum Rules on Nuclei Authors: Mikhail Gorchtein, Timothy Hobbs, J. Timothy Londergan, Adam P. Szczepaniak Categories: nucl-th hep-ph Comments: 8 pages, 4 figures, 2 tables \\ We revisit the photo-absorption sum rule for real Compton scattering from the proton and from nuclear targets. In analogy with the Thomas-Reiche-Kuhn sum rule appropriate at low energies, we propose a new "constituent quark model" sum rule that relates the integrated strength of hadronic resonances to the scattering amplitude on constituent quarks. We study the constituent quark model sum rule for several nuclear targets. In addition we extract the $\alpha=0$ pole contribution for both proton and nuclei. Using the modern high energy proton data we find a significant $\alpha=0$-pole contribution in contrast with the original findings by Damashek and Gilman. \\ ( http://arxiv.org/abs/1110.5982 , 284kb) ------------------------------------------------------------------------------ \\ arXiv:1110.6088 Date: Thu, 27 Oct 2011 14:27:05 GMT (19kb) Title: Relativistic Mean Field in $A\approx$80 nuclei and low energy proton reactions Authors: Chirashree Lahiri and G. Gangopadhyay Categories: nucl-th Comments: To appear in Physical Review C \\ Relativistic Mean Field calculations have been performed for a number of nuclei in mass $A\approx$80 region. Ground state binding energy, charge radius and charge density values have been compared with experiment. Optical potential have been generated folding the nuclear density with the microscopic nuclear interaction DDM3Y. S-factors for low energy ($p,\gamma$) and ($p,n$) reactions have been calculated and compared with experiment. \\ ( http://arxiv.org/abs/1110.6088 , 19kb) ------------------------------------------------------------------------------ \\ arXiv:1110.6093 Date: Thu, 27 Oct 2011 14:41:06 GMT (54kb) Title: Proton dripline in a new formula for nuclear binding energy Authors: Chirashree Lahiri and G. Gangopadhyay Categories: nucl-th Comments: To appear in Int. J. Mod. Phys. E \\ The location of the proton dripline in a new phenomenological mass formula is calculated. Predictions of different mass formulas for the dripline are compared. The implications of the new mass formula for rapid proton nucleosynthesis beyond $^{56}$Ni are discussed. It is seen that the new formula indicates that masses up to A=80 are easily synthesized in a typical X-ray burst. \\ ( http://arxiv.org/abs/1110.6093 , 54kb) ------------------------------------------------------------------------------ \\ arXiv:1110.6134 Date: Thu, 27 Oct 2011 16:23:42 GMT (619kb) Title: Systematic investigation of the rotational bands in nuclei with $Z \approx 100$ using a particle-number conserving method based on a cranked shell model Authors: Zhen-Hua Zhang, Xiao-Tao He, Jin-Yan Zeng, En-Guang Zhao, and Shan-Gui Zhou Categories: nucl-th nucl-ex Comments: 20 pages, 23 figures, submitted to Phys. Rev. C. arXiv admin note: text overlap with arXiv:1101.3607 \\ The rotational bands in nuclei with $Z \approx 100$ are investigated systematically by using a cranked shell model (CSM) with the pairing correlations treated by a particle-number conserving (PNC) method, in which the blocking effects are taken into account exactly. By fitting the experimental single-particle spectra in these nuclei, a new set of Nilsson parameters ($\kappa$ and $\mu$) and deformation parameters ($\epsilon_2$ and $\epsilon_4$) are proposed. The experimental kinematic moments of inertia for the rotational bands in even-even, odd-$A$ and odd-odd nuclei, and the bandhead energies of the 1-quasiparticle bands in odd-$A$ nuclei, are reproduced quite well by the PNC-CSM calculations. By analyzing the $\omega$-dependence of the occupation probability of each cranked Nilsson orbital near the Fermi surface and the contributions of valence orbitals in each major shell to the angular momentum alignment, the backbending mechanism in this region is understood clearly. \\ ( http://arxiv.org/abs/1110.6134 , 619kb) %-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%- ------------------------------------------------------------------------------ \\ arXiv:1010.3708 (*cross-listing*) Date: Mon, 18 Oct 2010 20:01:13 GMT (38kb) Date (revised v2): Thu, 27 Oct 2011 17:05:59 GMT (42kb) Title: A possible determination of the quark radiation length in cold nuclear matter Authors: R. B. Neufeld, I. Vitev, B. W. Zhang Categories: hep-ph nucl-ex nucl-th Comments: 8 pages, 4 figures Journal-ref: Physics Letters B, Vol. 704, Iss. 5, 2011, Pp. 590-595 \\ We calculate the differential Drell-Yan production cross section in proton-nucleus collisions by including both next-to-leading order perturbative effects and effects of the nuclear medium. We demonstrate that dilepton production in fixed target experiments is an excellent tool to study initial-state parton energy loss in large nuclei and to accurately determine the stopping power of cold nuclear matter. We provide theoretical predictions for the attenuation of the Drell-Yan cross section at large values of Feynman $x_F$ and show that for low proton beam energies experimental measurements at Fermilab's E906 can clearly distinguish between nuclear shadowing and energy loss effects. If confirmed by data, our results may help determine the quark radiation length in cold nuclear matter $X_0 \sim 10^{-13}$ m. \\ ( http://arxiv.org/abs/1010.3708 , 42kb) ------------------------------------------------------------------------------ \\ arXiv:1110.5926 (*cross-listing*) Date: Wed, 26 Oct 2011 20:32:31 GMT (931kb) Title: "Hard probes" of strongly-interacting atomic gases Authors: Yusuke Nishida Categories: cond-mat.quant-gas hep-ph nucl-th Comments: 29 pages, 9 figures Report-no: MIT-CTP 4311; LA-UR-11-11809 \\ We investigate properties of an energetic atom propagating through strongly-interacting atomic gases. We use operator product expansions to systematically compute quasiparticle energies and its scattering rates both in two-component Fermi gas and identical Bose gas. Reasonable agreement with recent quantum Monte Carlo simulations even at relatively small momentum k/kF>1.5 indicates that our large momentum expansions are valid in a wide range of momentum. We also study differential scattering rates when a third species of atom is shot into atomic gases. Because the number density of the target atomic gas contributes to the forward scattering only, its contact density gives the leading contribution to the backward scattering. Therefore, such an experiment can be used to measure the contact density and thus provides a new local probe of strongly-interacting atomic gases. \\ ( http://arxiv.org/abs/1110.5926 , 931kb) ------------------------------------------------------------------------------ \\ arXiv:1110.5985 (*cross-listing*) Date: Thu, 27 Oct 2011 05:02:16 GMT (300kb) Title: How sensitive is the neutron star r-mode instability window to the density dependence of nuclear symmetry energy? Authors: De-Hua Wen, W. G. Newton, Bao-An Li Categories: astro-ph.SR nucl-ex nucl-th Comments: 10 pages, 6 figures, submitted to Physical Review C \\ Using a simple model of a neutron star with a perfectly rigid crust constructed with a set of crust and core equations of state that span the range of nuclear experimental uncertainty in the symmetry energy, we calculate the instability window for the onset of the Chandrasekhar-Friedmann-Schutz (CFS) instability in r-mode oscillations for canonical neutron stars ($1.4 M_{\odot}$) and massive neutron stars ($2.0 M_{\odot}$). The crustal thickness is calculated consistently with the core equation of state (EOS). The EOSs are calculated using a simple model for the energy density of nuclear matter and probe the dependence on the symmetry energy by varying the slope of the symmetry energy at saturation density $L$ from 25 MeV (soft symmetry energy and EOS) to 115 MeV (stiff symmetry energy and EOS) while keeping the EOS of symmetric nuclear matter fixed. The instability window is reduced by a frequency of up to $\approx150Hz$ from the softest to the stiffest EOSs and by $\approx 100$ Hz from $1.4 M_{\odot}$ to $2.0 M_{\odot}$ stars for a fixed EOS. Where temperature estimates are available, the observed neutron stars in low mass X-ray binaries (LMXBs) have frequencies below the instability window for the $1.4 M_{\odot}$ models, while some LMXBs fall within the instability window for $2.0 M_{\odot}$ stars if the symmetry energy is relatively stiff, indicating that a softer symmetry energy is more consistent with observations within this model. The critical temperature, below which no star can reach the instability window without exceeding its Kepler frequency, varies by nearly an order of magnitude from soft to stiff symmetry energies. When the crust thickness and core EOS are treated consistently, a thicker crust corresponds to a lower critical temperature, the opposite result to previous studies in which the transition density was independent of the core EOS. \\ ( http://arxiv.org/abs/1110.5985 , 300kb) ------------------------------------------------------------------------------ \\ arXiv:1110.6004 (*cross-listing*) Date: Thu, 27 Oct 2011 08:13:47 GMT (57kb) Title: Hard Pion Chiral Perturbation Theory: What is it and is it relevant for $\eta^\prime$ decays? Authors: Johan Bijnens (Lund) Categories: hep-ph nucl-th Comments: 4 pages, Talk presented at the PrimeNet meeting, Meson Physics in Low-Energy QCD, September 26 - 28, 2011, Forschungszentrum Juelich, Germany Report-no: LU TP 11-39 \\ In this talk I give a short introduction to hard pion Chiral Perturbation Theory and an overview of the available applications $K\to\pi\pi$, $B,D\to D,\pi,K,\eta$ semileptonic decays and $\chi_{c0,2}\to\pi\pi,KK$. It is pointed out that the reults for the semileptonic decays obey the LEET relation between $f_+$ and $f_-$. \\ ( http://arxiv.org/abs/1110.6004 , 57kb) ------------------------------------------------------------------------------ \\ arXiv:1110.6074 (*cross-listing*) Date: Thu, 27 Oct 2011 13:18:55 GMT (128kb) Title: Couplings of light I=0 scalar mesons to simple operators in the complex plane Authors: B. Moussallam Categories: hep-ph nucl-th Comments: 31 pages, 5 figures \\ The flavour and glue structure of the light scalar mesons in QCD are probed by studying the couplings of the I=0 mesons $\sigma(600)$ and $f_0(980)$ to the operators $\bar{q}q$, $\alpha_s G^2$ and to two photons. The Roy dispersive representation for the $\pi\pi$ amplitude $t_0^0(s)$ is used to determine the pole positions as well as the residues in the complex plane. On the real axis, $t_0^0$ is constrained to solve the Roy equation together with elastic unitarity up to the $K\Kbar$ threshold leading to an improved description of the $f_0(980)$. The problem of using a two-particle threshold as a matching point is discussed. A simple relation is established between the coupling of a scalar meson to an operator $j_S$ and the value of the related pion form-factor computed at the resonance pole. Pion scalar form-factors as well as two-photon partial-wave amplitudes are expressed as coupled-channel Omn\`es dispersive representations. Subtraction constants are constrained by chiral symmetry and experimental data. Comparison of our results for the $\bar{q}q$ couplings with earlier determinations of the analogous couplings of the lightest I=1 and $I=1/2$ scalar mesons are compatible with an assignment of the $\sigma$, $\kappa$, $a_0(980)$, $f_0(980)$ into a nonet. Concerning the gluonic operator $\alpha_s G^2$ we find a significant coupling to both the $\sigma$ and the $f_0(980)$. \\ ( http://arxiv.org/abs/1110.6074 , 128kb) ------------------------------------------------------------------------------ \\ arXiv:1110.6102 (*cross-listing*) Date: Thu, 27 Oct 2011 15:01:01 GMT (205kb) Title: Hadron tomography through Wigner distributions Authors: Cedric Lorce and Barbara Pasquini Categories: hep-ph nucl-th Comments: 6 pages, 1 figure, 1 table, Prepared for the Third International Workshop on Transverse Polarization Phenomena in Hard Scattering (Transversity2011), Veli Lo\v{s}inj, Croatia, 29 Aug - 2 Sep 2011 \\ We study the Wigner functions of the nucleon which provide multidimensional images of the quark distributions in phase space and combine in a single picture all the information contained in the generalized parton distributions (GPDs) and the transverse-momentum dependent parton distributions (TMDs). In particular, we present results for the distribution of unpolarized quarks in a longitudinally polarized nucleon obtained in a light-cone constituent quark model. Treating the Wigner distribution as it was a classical distribution, we obtain the quark orbital angular momentum and compare it with alternative definitions given in terms of the GPDs and the TMDs. \\ ( http://arxiv.org/abs/1110.6102 , 205kb) ------------------------------------------------------------------------------ \\ arXiv:1110.6147 (*cross-listing*) Date: Thu, 27 Oct 2011 18:11:46 GMT (17kb) Title: An Analytical Evaluation For The Integral Of Two Spherical Bessel Functions With An Additional Exponential And Polynomial Factor Authors: R. Mehrem Categories: math-ph math.MP nucl-th Comments: 7 Pages \\ The integrals $\threej{\Llo}{\Llt}{\Llth} {0}{0}{0}\,\int_0^\infty \,r^{\Llth+1}\,e^{-\alpha r}\,j_\Llo(k_1r)\, j_\Llt(k_2r)\,dr$ and $\threej{\Llo}{\Llt}{\Llth} {0}{0}{0}\,\int_0^\infty \,r^{\Llth+2}\,e^{-\alpha r}\,j_\Llo(k_1r)\, j_\Llt(k_2r)\,dr$ are evaluated analytically. The result is a finite sum over the associated Legendre function of the second kind. \\ ( http://arxiv.org/abs/1110.6147 , 17kb) ------------------------------------------------------------------------------ \\ arXiv:1110.6156 (*cross-listing*) Date: Thu, 27 Oct 2011 18:47:13 GMT (668kb) Title: Chiral effective theory with a light scalar and lattice QCD Authors: J. Soto, P. Talavera and J. Tarr\'us Categories: hep-ph hep-lat nucl-th Comments: 26 pages, 8 figures \\ We extend the usual chiral perturbation theory framework ($\chi$PT) to allow the inclusion of a light dynamical isosinglet scalar. Using lattice QCD results, and a few phenomenological inputs, we explore the parameter space of the effective theory. The extended theory collects already at LO the ball park contribution to the pion mass and decay constant, thus achieving an accuracy that is comparable to the one of the standard $\chi$PT at NLO results. We check explicitly that radiative corrections do not spoil this behavior and keep the theory stable under mild variations of the parameters. The parameter sets that are compatible with the current mass and width of the sigma resonance turn out to reproduce the experimental values of the S-wave pion-pion scattering lengths very accurately. We also extract the average value of the two light quark--masses and evaluate the impact of the dynamical singlet field in the low--energy constants $\bar{l}_3$ and $\bar{l}_4$ of $\chi$PT. We emphasize that more accurate lattice data on the quark--mass dependence of the pion mass and decay constant would allow for a precise QCD extraction of the sigma resonance mass and decay width. \\ ( http://arxiv.org/abs/1110.6156 , 668kb) %%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%% ------------------------------------------------------------------------------ \\ arXiv:0711.3690 replaced with revised version Wed, 26 Oct 2011 20:01:10 GMT (2082kb) Title: Mechanisms of proton-proton inelastic cross-section growth in multi-peripheral model within the framework of perturbation theory. Part 2 Authors: I. V. Sharf, G. O. Sokhrannyi, A. V. Tykhonov, K. V. Yatkin, N. A. Podolyan, M. A. Deliyergiyev, V. D. Rusov Categories: nucl-th Comments: 11 pages, 10 figures \\ ( http://arxiv.org/abs/0711.3690 , 2082kb) ------------------------------------------------------------------------------ \\ arXiv:1103.1329 (*cross-listing*) replaced with revised version Wed, 26 Oct 2011 21:41:50 GMT (296kb,D) Title: Quarkonium dissociation in quark-gluon plasma via ionization in magnetic field Authors: Kevin Marasinghe, Kirill Tuchin Categories: hep-ph nucl-ex nucl-th Comments: 16 pages, 4 figures; v2: discussion and references added, typos fixed; v3: discussion section expanded \\ ( http://arxiv.org/abs/1103.1329 , 296kb) ------------------------------------------------------------------------------ \\ arXiv:1105.5360 replaced with revised version Wed, 26 Oct 2011 21:44:10 GMT (517kb,D) Title: J/Psi dissociation in parity-odd bubbles Authors: Kirill Tuchin Categories: nucl-th hep-ph nucl-ex Comments: 11 pages, 5 figures; v2: more discussions added \\ ( http://arxiv.org/abs/1105.5360 , 517kb) ------------------------------------------------------------------------------ \\ arXiv:1106.2276 (*cross-listing*) replaced with revised version Thu, 27 Oct 2011 11:24:02 GMT (164kb) Title: Exploring Three-Nucleon Forces in Lattice QCD Authors: Takumi Doi (Tsukuba U., GSPAS), Sinya Aoki, (Tsukuba U., GSPAS and Tsukuba U., CCS), Tetsuo Hatsuda (Tokyo U. and Tokyo U., IPMU, and Nishina Ctr., RIKEN), Yoichi Ikeda (Tokyo Inst. Tech.), Takashi Inoue (Nihon U., Fujisawa), Noriyoshi Ishii (Tsukuba U., CCS), Keiko Murano (Nishina Ctr., RIKEN), Hidekatsu Nemura (Tohoku U.), Kenji Sasaki (Tsukuba U., GSPAS), for HAL QCD Collaboration Categories: hep-lat hep-ph nucl-ex nucl-th Comments: 16 pages, 7 figures. v2: a reference added, typos corrected Report-no: UTHEP-630 \\ ( http://arxiv.org/abs/1106.2276 , 164kb) %%%---%%%---%%%---%%%---%%%---%%%---%%%---%%%---%%%---%%%---%%%---%%%---%%%--- For subscribe options to combined physics archives, e-mail To: physics@arXiv.org, Subject: subscribe ----------------------------------------------------------------------------- For help on viewing and making submissions, see http://arXiv.org/help/ For a list of archive mirror sites, see http://arXiv.org/servers.html ----------------------------------------------------------------------------- Third-party submissions cause excessive problems. Author self-submissions are exceedingly preferred. 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